No abstract

Catalytic reduction of the diimine linkages of 11,13-dimethyl-1,4,7,10-tetraazacyclotrideca-11,13-dienenickel(II) hexafluorophosphate, [Ni( [ 13 ] dieneNa)] (PF6)2, and 12,14-dimethyl-1,4,8,11 -tetraazacyclotetradeca-12,14-dienenickel(II) hexafluorophosphate, [Ni( [ 14]dieneN4) ] (PFe) 2, in aqueous solution over Raney nickel yields Ni(II) complexes containing the fully reduced, dimethyl-substituted macrocyclic ligands. Conversion of the PFe™ salts to NO3™ derivatives has been accomplished by column chromatography. Compounds with a variety of other anions have been prepared by metathetical reactions on solutions of the NO3" complexes. Ten new complexes have been characterized on the basis of elemental analyses, conductivity and magnetic susceptibility measurements, and infrared and electronic spectral studies. [Ni([13]aneN4)]X2 and [Ni([ 14]aneN4)]X2 where X™ = PFe™ and L contain singlet ground-state Ni(II) and the planar forms of both macrocyclic ligands. Axial coordination occurs when X™ = Cl™, Br™, and NO3™ and complexes of formulation [Ni([14]aneN4)X2] have been characterized as high spin tetragonal. Two complexes, [NÍ2([13]aneN4)20x](PF6)2 and [Ni2([14]aneN4)20x](PF6)2, are dimers which contain oxalato bridging groups. These two compounds, along with monomeric [Ni([14]aneN4)(SCN)2],exhibit pseudooctahedral Ni(II) spectral characteristics and must contain folded forms of the macrocyclic ligands. Analysis of electronic spectral data for the tetragonal complexes gives a Dq*y of 1470 cm™1 for the dimethyl-substituted 14-membered ligand. This value is nearly the same as that reported for cyclam which leads us to conclude that substitution of two methyl groups on the cyclam ring has negligible steric and electronic effects.

No abstract

No abstract

Die katalytische Reduktion der Diimin‐Bindungen in den makrocyclischen Ni‐Komplexen (I) führt zu den Komplexen (IIa) mit vollständig reduzierten Liganden.